Crankshaft oil scraper ring

Abstract

The utility model relates to sealing technology and can be used for sealing shafts with radial runout and axial vibrations. A crankshaft oil scraper ring, comprising a split housing, consists of an upper half-ring 1 and a lower half-ring 2 secured by a locking element 3, located in a housing for mounting the locking element on the outer surface of the ring such that half of the housing for mounting the locking element is located on each edge of the half-rings with the ability to mount the locking element. Preferably, the locking element is a threaded screw, and the housing for mounting the locking element has an internal thread. On the inner surface of the ring, there is a stuffing box 4 over the entire surface for mounting a cord packing 6, and the cord packing is a cord containing 80-95% PTFE and 5-20% graphite-filled PTFE composite.The technical result is an increase in the reliability of the shaft operation by adding a strand packing, in particular made of Teflon graphite, to the oil-scraping ring of the stuffing box, and by securing the half rings together with a locking element mounted on the outer surface of the ring in the housing. 5 ref. cl., 4 fig.

Description

[0001] The claimed utility model relates to sealing technology and can be used for sealing shafts with radial runout and axial vibrations.

[0002] Technology Level

[0003] A crankshaft oil deflector is known, which is part of the Ingersoll Rand 2HHE-2 two-row piston compressor for compression and delivery of gas under pressure, access mode: https: / / www.compressorworld.com / brand-category / 1531 / 6261 / ingersoll-rand-two-stage-piston-air-compressors (date of access: 11 / 26 / 2025). To seal the place where the crankshaft exits the compressor crankcase, an oil scraper ring is installed on the journal of the front part of the crankshaft. During engine operation, this ring, due to centrifugal force, "dumps" the oil back into the area where it flows into the compressor sump. The oil scraper ring consists of two halves. These halves are installed on the crankshaft journal and tightened with fastening screws.A disadvantage of the solution used in the Ingersoll Rand 2HHE-2 compressor is the loose fit of the oil scraper ring to the crankshaft journal, through which oil leaks along the crankshaft from the compressor crankcase, leading to a decrease in the oil level in the compressor sump and contamination of surrounding compressor parts.

[0004] A multi-layer sealing ring with a conical surface and a sealing device are known from the prior art according to patent US4212473, which discloses a multi-section sealing ring for sealing, intended for placement in an annular groove formed in a rotating surface, formed by concentric rings of different diameters, tightly adjacent to each other, wherein the cut out parts of said sealing elements are offset circumferentially relative to each other and press adjacent internal and external peripheral surfaces of said sealing elements into tight contact.

[0005] Also known is an erosion-resistant flow control valve according to international patent application WO2021150592, filed by Schlumberger, in which the leakage prevention mechanism includes a flow restriction ring comprising a first C-ring, a second C-ring, and an inner ring located between the first and second spring rings. The piston may include a main body and a retainer connected to the main body. The flow restriction ring may be located on the outer surface of the retainer.

[0006] As a technical solution closest to the claimed invention, a split oil seal for the main bearing of the engine crankshaft, known from patent SU 1451381, is proposed. It consists of two half-rings of packing secured with a pin, with the ends of the half-rings in the groove along the shaft direction. A disadvantage of the prototype according to patent SU 1451381 is the use of packing for shafts with low shaft speeds. On high-speed rotating shafts, this packing does not fit tightly to the crankshaft and is less hermetically sealed, thereby affecting the reliability of the compressor. Another disadvantage is the fact that the half-rings are secured with a pin, which can lead to mechanical loosening during operation and does not provide a sufficiently secure fastening.

[0007] A technical problem with existing sealing rings is their lack of reliability. Existing solutions fail to provide reliable sealing of compressor components and / or, due to their design features, are prone to failure during operation. This leads to insufficient adaptation to dynamic load changes, which impacts the reliability and durability of the rotor section.

[0008] The problem, which the claimed utility model is aimed at solving, is the creation of a design of an oil-scraping ring with a cord packing on the inner surface and a fixing element on the outer surface.

[0009] Essence Revealed

[0010] The technical result is to increase the reliability of the crankshaft operation by adding a bundle packing, in particular made of Teflon with graphite, to the oil-scraping ring of the stuffing box, and fixing the half rings together with a fixing element, which is installed on the outer surface of the ring in the housing.

[0011] The stated technical result is achieved by the following design of the crankshaft oil scraper ring.

[0012] A crankshaft oil control ring comprising a split housing consists of an upper half ring 1 and a lower half ring 2 secured by a locking element 3 located in a housing for installing the locking element on the outer surface of the ring so that half of the housing for installing the locking element is located on each edge of the half rings with the ability to install the locking element. Preferably, the locking element is a threaded screw, and the housing for installing the locking element has an internal thread. On the inner surface of the ring, there is a seal chamber 4, formed along the entire circumference of the ring, for installing a cord packing 6, and the cord packing is a cord containing 80-95% PTFE Teflon and 5-20% graphite-filled PTFE composite.

[0013] The effect of installing a ring made of half rings with a cord packing made on a Teflon base with the addition of graphite, which is installed in the seal chamber, the half rings of which are fixed by a locking element installed in the housing on the outer surface of the ring, is manifested in improved tightness, reduced friction and the likelihood of crankshaft failures, which ultimately increases its reliability and durability in operation.

[0014] Brief description of drawings

[0015] Fig. 1 - comparison with the prototype: top - prototype, bottom - proposed solution;

[0016] Fig. 2 - oil release ring with cord packing;

[0017] Fig. 3 - diagram of installation of oil scraper ring in piston compressor;

[0018] Fig. 4 - diagram of the installation of the oil scraper ring, where

[0019] 1 - upper half ring;

[0020] 2 - lower half ring;

[0021] 3 - fixing element;

[0022] 4 - stuffing box chamber;

[0023] 5 - crankshaft;

[0024] 6 - rope packing;

[0025] 7 - housing for installing the fixing element.

[0026] Implementation of a utility model

[0027] The oil scraper ring is a unit designed to provide effective sealing and protect the engine from oil leakage, preferably in the crankshaft design, although other embodiments are possible. The crankshaft oil scraper ring comprises a split housing consisting of an upper half ring 1 and a lower half ring 2. The upper 1 and lower 2 half rings constitute the main supporting frame of the oil scraper ring, providing its rigidity and shape. They perform the function of separating and directing the oil thrown off the surface of the crankshaft 5, preventing excess oil from leaking from the engine crankcase into the external environment. The half rings also serve as a housing for the stuffing box 4 on the inner surface, where the cord packing is attached. The upper half ring 1 and the lower half ring 2 are connected to each other by a locking element 3.To prevent loosening and deformation of the fixing element 3, on the outer surface of the ring there is a housing for installing the fixing element 3 so that half of the housing for installing the fixing element 3 is located on each edge of the half rings with the possibility of installing the fixing element 3 inside.

[0028] The locking element 3 is screwed into the housing for mounting the locking element 7 on each edge of the half ring, securing the upper 1 and lower 2 half rings together. In the preferred embodiment, the housing for mounting the locking element 7 comprises an internal thread, and the locking element 3 is a threaded screw. This maximizes the durability of the fastening and minimizes oil clogging. However, other types of fastening installed in a protective housing on the half ring rings may be considered within the scope of the invention.

[0029] Seal chamber 4 is formed on the inner surface of the ring and has a recess or cavity around its entire circumference for installing the packing (cord) packing. Seal chamber 4 ensures uniform distribution of packing pressure 6 across the surface of shaft 5, creating a sealed space in which packing 6 fits tightly against crankshaft 5, preventing oil leakage due to shaft rotation.

[0030] A packing (cord) is installed in the seal chamber 4. In the embodiment of the utility model, the cord packing 6 is installed. This is a sealing element installed within the seal chamber on the inner surface of the oil scraper ring in contact with the crankshaft 5. Cord packing 6 tightly compresses the crankshaft 5, creating a hermetic seal that prevents oil leakage. The packing prevents oil from entering areas where it is unwanted, extending performance and increasing reliability. Implementations are known in which, to improve sealing characteristics, cord packing 6 is laid in several layers within the seal chamber 4.

[0031] In a preferred embodiment, the cord packing 6 is a cord made from a Teflon base with the addition of graphite. In the most preferred embodiment, the cord packing is a cord containing 80-95% Teflon PTFE and 5-20% graphite-filled PTFE composite. In practice, this ratio of the components of the cord packing made from a Teflon base with the addition of graphite has been confirmed to be optimal for use in a crankshaft. When the Teflon PTFE content is less than 80%, the hydrophobicity decreases, which leads to increased friction and wear of the components. When the PTFE content is more than 95%, the mechanical strength of the packing decreases, increasing the likelihood of deformation and failure. When the content of the graphite-filled composite is less than 5%, the lubricating effect and heat dissipation are reduced, increasing the risk of overheating and accelerated wear.A graphite content exceeding 20% ​​can increase the packing's hardness and brittleness, leading to cracking and reduced sealing performance. Failure to maintain the optimal composition reduces the service life of the cord packing 6 and can lead to oil leaks and damage to the crankshaft 5 due to increased friction and wear.

[0032] The oil scraper ring is installed around crankshaft 5. It connects to the pistons and converts the pistons' reciprocating motion into rotational motion. The oil scraper ring fits snugly against the surface of crankshaft 5 to drain excess oil, preventing oil from leaking from the working fluid into the outside environment.

[0033] The claimed utility model is implemented as follows.

[0034] During crankshaft operation, oil, under the influence of centrifugal force and pressure, flows onto the oil scraper ring mounted on the crankshaft. It interacts with the packing cord 6, creating a sealing barrier that prevents oil leaks and ensures stable lubrication pressure. The packing cord's composite composition (80-95% PTFE and 5-20% graphite-filled PTFE composite) reduces wear on the ring surface and the upper 1 and lower 2 half rings, minimizing heat buildup and fatigue damage.

[0035] Locking element 3 stabilizes the position of half rings 1 and 2, preventing them from shifting or loosening under vibration and loads, thereby increasing the reliability of the connection. Thus, all elements of the crankshaft oil scraper ring work to seal the rotating crankshaft 5, drain excess oil, and prevent its leakage from the engine. Upper 1 and lower 2 half rings form the structural basis of the seal chamber 4, inside which, over the entire inner surface, a cord packing 6 is located, providing a seal. A housing for mounting the locking element 7 with an internal thread on the half rings and threaded screws secure the entire structure, preventing delamination and displacement of the elements during engine operation. Crankshaft 5 serves as the axis of rotation and the sealing object for the oil scraper ring. This design guarantees increased reliability of the engine crankshaft oil scraper assembly.

Claims

1. A crankshaft oil scraper ring having a split housing consisting of an upper half-ring and a lower half-ring secured with a locking element, characterized in that on the inner surface of the ring there is a sealing chamber along the entire inner surface for installing a bundle packing, and on the outer surface of the ring there is a housing for installing a locking element so that half of the housing for installing a locking element is located on each edge of the half-rings with the possibility of installing a locking element inside, and a bundle packing is installed in the sealing chamber, which is a bundle made on a Teflon base with the addition of graphite.

2. The crankshaft oil scraper ring according to claim 1, characterized in that the bundle packing is a bundle containing 80-95% PTFE and 5-20% graphite-filled PTFE composite.

3. The crankshaft oil scraper ring according to claim 1, characterized in that the housing for installing the locking element contains an internal thread.

4. The crankshaft oil scraper ring according to paragraph 1, characterized in that the locking element is a threaded screw.

5. The crankshaft oil scraper ring according to paragraph 1, characterized in that the bundle packing is placed in the seal chamber in several layers.

Images